This site introduces unknown Emanuel Bach (C. P. E. Bach).
ChatGPT4o writes as follows (please note that it may not be accurate):
Emanuel Bachʼs Sonata in D minor Wq. 50-04 (H. 139) is one of the works that showcases his unique musical style. This sonata consists of three movements, each demanding different emotions and techniques. The first movement has a graceful and light atmosphere, captivating the listener with its charm. The following second movement possesses deep emotion and introspective beauty, highlighting Bachʼs expressive melodies. The final third movement is a lively and energetic finale, characterized by technical prowess and dynamic development. This sonata is an important work that demonstrates Emanuel Bachʼs innovative musical language and his role as a bridge to the Classical era.